The result left champions Lille third with 47 points from 27 games. Lyon moved up to 43 points.
Lille, who occupy the Champions League play-off spot, are one point in front of Saint-Etienne after Les Verts recorded a 2-1 win at Valenciennes.
Lyon, knocked out of the Champions League by APOEL Nicosia this week, had defender Dejan Lovren sent off with 19 minutes left but first-half goals by Alexandre Lacazette and Lisandro Lopez proved enough to get all three points.
Aurelien Chedjou reduced the arrears for Lille with a downward header from a corner on the stroke of half-time.
Lyon went ahead in the 12th minute when Lacazette headed in a Mouhamadou Dabo cross. Lopez made it 2-0 in the 38th with a superb curling shot from the edge of the box.
Manchester United manager Sir Alex Ferguson was spotted in the stand at Stade Gerland, perhaps casting an eye over Belgian playmaker Eden Hazard who has said he may leave Lille at the end of the season.
Saint-Etienne, who host arch-rivals Lyon in the next round of matches, also improved their chances of playing in next season's Champions League by snatching a 2-1 win in an ill-tempered game at Valenciennes.
Both teams finished with 10 men after Valenciennes midfielder Carlos Sanchez was sent off after four minutes for a rough tackle and Saint-Etienne's Jean-Pascal Mignot was shown a straight red card in the 33rd.
The hosts took the lead in the 69th minute through Vincent Aboubakar who scored from close range following a Foued Kadir cross.
Saint-Etienne equalised four minutes later as Albin Ebondo perfectly set up Pierre-Emerick Aubameyang.
In the 77th minute Bakary Sako put the visitors ahead when he poked the ball home after Laurent Battles struck the post.
Sako then hit the bar twice for St Etienne.
Toulouse drew 1-1 at home to Lorient.
A Lucas Mareque own goal put Toulouse ahead before Innocent Emeghara levelled in the 61st minute.
Former France winger Sidney Govou's season looks over after he sustained an Achilles injury in Evian Thonon Gaillard's 3-2 home defeat by Sochaux.
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